The effects of low-frequency vibrations on speckle correlation fringes
have been investigated. The relatively short capture time of the came
ra in the low-frequency case may yield usable fringe contrast in spite
of vibration. It has been shown that the fringes also shift due to th
e vibration. The study is in agreement with experimental observations
of good-contrast correlation fringes even if the object is not on a vi
bration-isolated table. Some such experimental observations are also p
resented. (C) 1998 Society of Photo-Optical Instrumentation Engineers.
[S0091-3286(98)03605-8].